KR20200130817A - Aggregate mixture for molding, mold, and molding method of mold - Google Patents

Abstract

An aggregate mixture for a mold containing an aggregate, a water-soluble caking agent, a water-soluble foaming agent, an aqueous release agent, and water.

Description

Aggregate mixture for molding, mold, and molding method of mold

The present disclosure relates to an aggregate mixture for a mold, a mold, and a method for forming a mold.

BACKGROUND ART Conventionally, a mold molding apparatus has been used in which a foamed mixture obtained by stirring a particulate aggregate, a water-soluble binder, and water is filled into a cavity of a heated mold by a press-fitting method to form a mold.

As this mold molding apparatus, for example, in Patent Document 1, a bottom opening of a hollow rectangular parallelepiped having a hollow cuboid which forms a rectangular parallelepiped and penetrates upward and downward is closed with a bottom plate, and an injection hole for injecting the foam mixture into the bottom plate is provided. A mixture storage means is provided that has a function as a stirring tank to stir the aggregate, water-soluble binder, and water by pouring, and a function as a press-in cylinder for receiving the mixture in order to press-in the mixture. A mold molding apparatus is disclosed in which a stopper means capable of closing a hole is provided.

[Patent Document 1] Japanese republished 2005-89984 publication

As described in Patent Document 1, the aggregate mixture containing aggregate, caking agent, foaming agent, and water is stirred and foamed to generate air bubbles, and the foamed aggregate mixture is press-fitted into the cavity of the heated mold to form a mold. The technology is known. In addition, when the molded mold is removed from the mold, the mold partially remains in the cavity of the mold, or cracks or flaws may occur in the mold. By the way, in order to suppress some such residuals, cracks, flaws, and the like, before press-fitting the aggregate mixture into the mold cavity, a release agent is applied to the cavity surface of the mold. In addition, as a release agent applied to the cavity surface of the mold, a release agent containing a non-reactive silicone type such as dimethyl silicone as a main component is generally used.

However, the work of applying the release agent to the mold is carried out every time the mold is molded, and as long as each application of the release agent prevents the simplification of the mold molding (for example, shortening the time in the repeated molding cycle). It is becoming a factor. In addition, at the time of application, the release agent may scatter in the surrounding environment.

For this reason, when molding a mold, it is required to not require or reduce the work of applying the release agent to the mold.

An object of the present disclosure is to provide an aggregate mixture for a mold, and a method for molding a mold, which does not require or can reduce the application of a release agent to a mold when molding a mold.

In addition, it is an object of the present invention to provide a mold having excellent releasability.

The said subject is solved by the following means.

<1> 　The aggregate mixture for a mold containing an aggregate, a water-soluble caking agent, a water-soluble foaming agent, an aqueous mold release agent, and water.

<2> 　 The water-soluble mold release agent described in <1> above, which is a chain structural substance having at least one functional group selected from a carboxyl group, a carbonyl group, a silanol group, and a phenol group having a proton donating agent acting as the water-soluble binder. Aggregate mixture for molding.

<3> The above <2, wherein the content of the aqueous release agent is 2.0 × 10 ^-7 mol/kg or more and 1.0 × 10 ^-4 mol/kg or less with respect to the mold aggregate mixture as an equivalent of the functional group acting as the water-soluble binder. The aggregate mixture for a mold described in >.

<4> 　 The aggregate mixture for molding according to any one of the above <1> to <3>, wherein the aqueous release agent has a performance that does not hinder the foaming action.

<5> 　 The above <1> to <1> to <1> containing at least one selected from a carbohydrate forming a glycosidic bond with the water-soluble mold release agent, and an inorganic salt and an organic salt that acts with a functional group of the water-soluble mold release agent. The aggregate mixture for a mold according to any one of 4>.

<6> 　 The aggregate for a mold according to any one of <1> to <5>, wherein the aggregate is at least one of natural silica sand and artificial sand.

<7> 　 The aggregate mixture for a mold according to any one of <1> to <6>, wherein the particle size (AFS index) of the aggregate is 40 or more and 120 or less.

<8> 　 The aggregate mixture for a mold according to any one of the above <1> to <7>, wherein the water-soluble foaming agent is a surfactant.

The aggregate mixture for a mold according to any one of the above <1> to <8> containing bubbles by <9>?

<10> 　 A mold containing an aggregate, a water-soluble caking agent, a water-soluble foaming agent, and an aqueous mold release agent.

<11>　a) Foamed aggregate to prepare a foamed aggregate mixture containing air bubbles by stirring the aggregate, water-soluble binder, water-soluble foaming agent, water-based mold release agent, and water-containing aggregate mixture mixture for a mold Mixture preparation process,

b) a filling step of filling the foamed aggregate mixture into a space for mold molding in a mold,

c) a mold-shaping process of evaporating the moisture of the charged foamed aggregate mixture to solidify the foamed aggregate mixture to form a mold, and

d) a takeout step of taking out the molded mold from the space for mold molding,

Molding method of a mold having a.

According to the present disclosure, it is possible to provide an aggregate mixture for a mold and a method for forming a mold, which does not require or can reduce the application of a release agent to a mold when molding a mold.

In addition, it is possible to provide a mold having excellent releasability.

Hereinafter, embodiments of the present disclosure will be described in detail.

In addition, in the present specification, the term "process" is not only an independent process, but also when the object is achieved, even when it cannot be clearly distinguished from other processes, the above process is also included in the term.

The aggregate mixture for a mold according to the present embodiment (hereinafter, also referred to simply as "aggregate mixture") contains an aggregate, a water-soluble caking agent, a water-soluble foaming agent, an aqueous mold release agent, and water.

The aggregate mixture for a mold according to the present embodiment is a composition used as a material for a mold. In addition, in the present specification, the term "template" is used as a meaning including a middle character.

The mold aggregate mixture according to the present embodiment does not require or can reduce the application of a mold release agent to a mold when molding a mold by having the above configuration.

The reason why this effect is exhibited is estimated as follows.

In the aggregate mixture for a mold according to the present embodiment, the mold release agent is contained and the mold release agent is aqueous, and when the aggregate mixture containing water is stirred and foamed, the aqueous mold release agent is preferably dispersed. The foamed aggregate mixture for molding is pressed into a cavity of a mold, and heat is supplied to the aggregate mixture from the heated mold to evaporate moisture to form a mold. Further, the foamed aggregate mixture for a mold is filled into the cavity by press fitting and pressed against the mold. For this reason, the aqueous releasing agent dispersed in the aggregate mixture at the interface portion between the mold and the aggregate mixture is extruded toward the interface side of the mold. In addition, at the interface portion, heat is provided to the aggregate mixture by contacting the heated mold, and the action of the functional groups of the aqueous mold release agent on the water-soluble binder is promoted by the heat and pressure. Further, the chain structural material, which is the main chain of the aqueous release agent, is concentrated and immobilized at the interface. Further, at the interface with the mold, the starting point of water evaporation due to heat also occurs from the inner direction of the cavity, and the internal pressure increases due to evaporation. For this reason, the aqueous releasing agent is continuously extruded on the interface side with the mold until the molding of the mold is completed, and the chain structural material of the aqueous releasing agent is concentrated at the interface with the mold. In such a structure, it is considered that when the mold is removed from the mold, good releasability is exhibited by the release agent contained in the mold, so that the operation of applying the release agent to the mold is not required or can be reduced.

Further, since the operation of applying the releasing agent to the mold is not required or can be reduced, simplification of mold molding (for example, reduction of time in repeated molding cycles) can be achieved.

Further, scattering of the releasing agent generated when the releasing agent is applied to the mold is reduced. In addition, since the aqueous release agent contained in the aggregate mixture is well dispersed in water as described above, it is difficult to scatter out of the aggregate mixture. By these, it is thought that scattering of the release agent to the surrounding environment is also suppressed.

Next, each component constituting the mold aggregate mixture according to the present embodiment will be described in detail.

〔Aqueous release agent〕

The aggregate mixture for molding according to the present embodiment contains an aqueous mold release agent.

Here, "aqueous" refers to an emulsion that is dispersed in water at room temperature (that is, 20° C.), and it is preferable that a mixture of pure water having the same volume at 1 atmosphere of 20° C. exhibits a uniform appearance.

In addition, the "release agent" refers to an additive that can improve the releasability of the surface of the mold formed by being contained in the aggregate mixture, compared to the mold formed without containing.

-Chain structure material-

It is preferable that the aqueous release agent is a substance having a chain structure (referred to as a "chain structure substance" in this specification). As a chain structure material, it represents, for example, a polymer compound having a carbon chain in which carbon atoms are arranged or a siloxane chain that is a skeleton of silicon.

・Performance that does not interfere with the foaming action

The oil component is dispersed in the aqueous emulsion. In addition, although many oil components have an antifoaming effect, in this embodiment, by appropriately selecting a surfactant contained in the emulsion, it is possible to impart a performance that does not interfere with the foaming action to the aqueous release agent. By doing so, stable foaming can be performed, and it becomes easy to control the viscosity of the aggregate mixture in the required range when filling the mold.

Here, a description will be given of an aqueous release agent having a performance that does not interfere with the foaming action. Based on 100 parts by mass of Flattery Sand, a type of aggregate, 1.0 parts by mass of polyvinyl alcohol, which is a type of water-soluble binder, 0.03 parts by mass of anionic surfactant, and 5.0 parts by mass of water, 1.0 parts by mass of a ``aqueous release agent'' [Viscosity A] (Pa·s) when foaming was further added and stirred for 5 minutes at 200 rpm, when stirred and mixed for 5 minutes at 200 rpm without adding “aqueous release agent” [Viscosity B] With respect to (Pa·s), when it is 100 times or less, the aqueous release agent is assumed to have "performance not to interfere with the foaming action".

Moreover, it is more preferable that [viscosity A] is 10 times or less with respect to [viscosity B], and the closer to 1 times, the more preferable.

·Functional group

It is preferable that the aqueous release agent has a functional group acting as a water-soluble binder. Here, the functional group will be described. The said functional group in this embodiment is a functional group which has a proton donor which imparts an acidic property. Examples of the functional group include a phenol group (-C ₆ H ₄ -OH), a carboxyl group (carboxyl group, -COOH), a carbonyl group (-C(=O)-), and a silanol group (-SiH ₂ OH). However, the functional group in this embodiment is not limited to the example of the functional group described above. That is, as the functional group in the present embodiment, any one having a proton donating agent can be used because it acts as a water-soluble binder.

・Equivalent amount of functional groups contained in the aggregate mixture

The content of the aqueous releasing agent is preferably 2.0×10 ^-7 mol/kg or more and 1.0×10 ^-4 mol/kg or less, in terms of the amount of the functional group in the aggregate mixture, that is, the equivalent of the functional group to the aggregate mixture, and 1.0×10 ^-6 mol/kg or more and 4.0×10 ^-5 mol/kg or less are more preferable. This functional group is one that is added in an appropriate amount by an aqueous release agent.

When the equivalent of the functional group contained in the aggregate mixture is 2.0 × 10 ^-7 mol/kg or more, the mold releasability from the mold is further improved. On the other hand, when the equivalent of the functional group is 4.0 × 10 ^-5 mol/kg or less, stable foaming can be performed, and the viscosity of the aggregate mixture when filling the mold can be easily controlled within the required range.

〔aggregate〕

The aggregate in this embodiment is not particularly limited, and any conventionally known aggregate can be used. For example, aggregates such as silica sand (for example, natural silica sand), alumina sand, olivine sand, chromite sand, zircon sand, and mullite sand may be mentioned. In addition, various artificial aggregates (so-called artificial sand) may be used.

Among these, at least one of natural silica sand and artificial sand is particularly preferable from the viewpoint of easy to obtain sufficient mold strength and to easily obtain a high aggregate regeneration rate even if the amount of the binder added to the aggregate is reduced.

As the particle size (that is, the AFS index) of the aggregate in this embodiment, AFS; AFS of 30 (JIS; 38) or higher; 150 (JIS; 243) or less are preferred, and AFS; 40 (JIS; 52) or higher AFS; 120 (JIS; 184) or less is more preferable.

The particle size (ie AFS index) is AFS; By being 30 or more, it is excellent in fluidity and the filling property at the time of molding a mold is improved. On the other hand, AFS; It is 150 or less and maintains good air permeability as a mold. In particular, AFS; If it is 40 or more, the aggregate is fine, the transferability of the mold having a fine shape is improved, and the mold strength is also increased. On the other hand, if the AFS is 120 or less, the sand is somewhat coarse and the handling property is improved, and regeneration can be performed easily.

In addition, in this specification, the particle size represents the particle size index measured by the particle size test method of casting sand described in JIS　Z　2601-1993 Annex 2.

The shape of the aggregate in the present embodiment is not particularly limited, and may be any shape such as an annular shape, a angular ring shape, a polygonal shape, and a pointed polygonal shape. Further, from the viewpoint of excellent fluidity, improved filling properties when molding a mold, and maintaining good air permeability as a mold, an annular shape is particularly preferred.

〔Water-soluble caking agent〕

The water-soluble caking agent is contained in order to impart a caking power to the aggregate from the viewpoint of maintaining the shape of the mold satisfactorily in the normal temperature and the temperature range of the molten metal to be poured.

In addition, water solubility means that it is soluble in water at room temperature (that is, 20° C.), and it is preferable that a mixed solution with pure water of the same volume at 1 atmosphere of 20° C. exhibits a uniform appearance.

Examples of the water-soluble binder in the present embodiment include sodium silicate (so-called water glass), potassium silicate (so-called potassium silicate), ammonium silicate, orthophosphate, pyrophosphate, trimetaphosphate, polymethaphosphate, colloidal silica, Inorganic salts and organic salts, such as colloidal alumina and alkyl silicates, which act with a functional group possessed by an aqueous release agent are mentioned.

Among these, sodium silicate (so-called water glass) and potassium silicate (so-called kali silicate) are more preferable.

Further, as sodium silicate (so-called water glass), the molar ratio (that is, the molecular ratio of SiO ₂ ·Na ₂ O) is preferably 1.2 or more and 3.8 or less, and more preferably 2.0 or more and 3.3 or less. Since the molar ratio is more than the lower limit, there is an advantage that deterioration of the water glass can be suppressed even in long-term storage at a low temperature. On the other hand, since the molar ratio is less than or equal to the upper limit, there is an advantage that it is easy to adjust the viscosity of the binder.

In addition, as the water-soluble binder, a water-soluble binder that will be described later and having foamability may also be used.

In addition, water-soluble binders may be used alone or in combination of two or more of those listed above.

The content of the water-soluble binder in the present embodiment in the aggregate is preferably set according to the type of binder and aggregate to be used, but is preferably 0.1% by mass or more and 20% by mass or less, and further 0.1% by mass or more and 10% by mass. % Or less is more preferable.

[Water-soluble foaming agent]

In addition, when shaping a mold using the aggregate mixture according to the present embodiment, it is preferable to mix it with an aggregate, a water-soluble binder, etc. using a water-soluble foaming agent, stir and foam. That is, it is preferable to prepare a foamed aggregate mixture to improve fluidity, and then to mold a mold.

In addition, water solubility means that it is soluble in water at room temperature (that is, 20° C.), and it is preferable that a mixed solution with pure water of the same volume at 1 atmosphere of 20° C. exhibits a uniform appearance.

It is more preferable that the water-soluble foaming agent has a function as a caking agent (that is, a water-soluble binder having foaming property). In addition, from the viewpoint of causing the above-described foaming in the aggregate mixture more efficiently, a water-soluble binder, which is an organic salt that has foamability and functions with a functional group of the aqueous release agent, and a carbohydrate that forms a glycosidic bond with the aqueous release agent, Water-soluble binders are preferred.

Examples of the foamable water-soluble binders include surfactants (specifically, anionic surfactants, nonionic surfactants, amphoteric surfactants, etc.), polyvinyl alcohol or derivatives thereof, saponins, starch or derivatives thereof, and And other sugars. In addition, as other saccharides, for example, cellulose and fructose as polysaccharides, acarbose as tetrasaccharides, raffinose, and maltotriose as trisaccharides, and maltose and sucratose as disaccharides , And trehalose, and the like, as monosaccharides, include glucose, fructose, and other oligosaccharides.

Examples of the anionic surfactant include sodium fatty acid, monoalkyl sulfate, sodium linear alkyl benzene sulfonate, sodium lauryl sulfate, and sodium ether sulfate. Examples of the nonionic surfactant include polyoxyethylene alkyl ether, fatty acid sorbitan ester, and alkyl polyglucoside. Examples of amphoteric surfactants include cocamidopropylbetaine, cocamidopropylhydroxysultaine, and lauryl dimethylaminoacetic acid betaine.

The water-soluble foaming agent may be used alone or in combination of two or more among those listed above.

The content of the water-soluble foaming agent in the present embodiment to the aggregate is preferably set according to the foaming agent to be used and the type of aggregate.

The total content of the anionic surfactant, the nonionic surfactant, and the amphoteric surfactant is preferably 0.001% by mass or more and 0.1% by mass or less, and more preferably 0.005% by mass or more and 0.05% by mass or less based on the aggregate.

The total content of polyvinyl alcohol and its derivatives, saponins, starch and its derivatives, and other saccharides is preferably 0.1% by mass or more and 20.0% by mass or less, and more preferably 0.2% by mass or more and 5% by mass or less based on the aggregate. Do.

〔water〕

The aggregate mixture for a mold according to the present embodiment contains water.

The content of water in the aggregate in this embodiment is preferably set according to the type of binder and aggregate used, but preferably 0.5% by mass or more and 10.0% by mass or less, and 1.5% by mass or more and 7.5% by mass or less. More preferable.

[Other compositions]

In addition, in addition to the above, a conventionally known composition such as a catalyst and an oxidation accelerator can be added to the aggregate mixture for a mold according to the present embodiment.

〔Kneading method〕

Preparation of the aggregate mixture for a mold according to the present embodiment is performed by mixing the various components described above. The order of addition and the kneading method are not particularly limited.

The kneading apparatus for kneading each of the above components is not particularly limited, and a conventionally known kneading apparatus is used. For example, a rotating/revolving mixer, an EIRICH/intensive mixer, and Sinto Simpson's Mix Muller are used.

〔How to shape the mold〕

The molding of the mold using the mold aggregate mixture according to the present embodiment may be molding by a molding machine or may be bench molding.

However, it is preferable to mix and agitate each of the above components to form a foamed aggregate mixture, and then press-fit into the heated mold molding space (so-called cavity) in a mold for mold molding to form. Further, it is more preferable to fill by injection during press-fitting.

More specifically, it is preferable to shape the mold according to the molding method including the following steps a) to d).

a) A foamed aggregate mixture preparation process in which foaming is generated in the aggregate mixture by stirring an aggregate mixture containing an aggregate, a water-soluble caking agent, a water-soluble foaming agent, an aqueous release agent, and water to prepare a foamed aggregate mixture containing air bubbles.

b) Filling process of filling the foamed aggregate mixture into the mold molding space (so-called cavity) in the mold

c) a mold molding process of evaporating the moisture of the filled foamed aggregate mixture to solidify the foamed aggregate mixture to form a mold

d) Take-out process to take out the molded mold from the space for mold molding

In the foamed aggregate mixture press-fit into the mold molding space of a mold heated to a high temperature, bubbles dispersed in the foamed aggregate mixture by stirring and water vapor generated from moisture in the foamed aggregate mixture are collected in the center of the mold by the heat of the heated mold. A phenomenon occurs. For this reason, a mold with a low packing density (i.e., solid content) of the aggregate, water-soluble binder, water-soluble foaming agent, and water-based mold release agent is formed in the center, whereas the surface is filled with aggregate, water-soluble binder, water-soluble foaming agent, and water-based mold release agent It becomes a mold with a high density (that is, the density of solids).

Since the water-based release agent present on the mold surface greatly affects the releasability of the mold from the mold, in this embodiment, in which the packing density of the water-based release agent on the surface is increased as described above, the release property by the water-based release agent is better exhibited. do. In addition, since the packing density of the aqueous release agent on the surface increases, it is also effective in reducing the amount of the aqueous release agent added.

In addition, in the mold, in order to check whether the density of the solids in the center portion is less than the density of the solids in the surface portion, the solids in the cross section and the surface of the center of the mold (i.e. aggregate, water-soluble binder, water-soluble foaming agent, and water-based release agent) It can be determined by visually checking the degree of packing.

Since the aggregate mixture improves the filling property in the mold forming space, and in order to improve the filling density, it is preferable to foam until it becomes a whipped cream shape. More specifically, it is preferable that the viscosity of the foamed aggregate mixture (i.e., the molded aggregate mixture after stirring) is 0.5 Pa·s or more and 10 Pa·s or less, and the viscosity is further 0.5 Pa·s or more and 8 Pa·s or less. More preferable.

In addition, the measurement of the viscosity of the expanded aggregate mixture (that is, the aggregate mixture for a mold after stirring) is performed as follows.

-How to measure-

The foamed aggregate mixture was put into a cylindrical container having an inner diameter of 42 mm having pores having a diameter of 6 mm at the bottom, and then a cylindrical weight having a weight of 1 kg and a diameter of 40 mm was mounted in the cylindrical container. By pressing with the weight of the weight, the foamed aggregate mixture is discharged from the pores of the cylindrical container. At this time, the time required to move the additional 50 mm is measured, and the viscosity of the expanded aggregate mixture is determined by the following equation. In addition, the temperature at the time of viscosity measurement is set to 20°C.

Formula μ=πD ⁴ P _p t/128L ₁ L ₂ S

μ: Viscosity [Pa·s]

D: Diameter of bottom pore [m]

P _p : Weight pressing force [Pa]

t: Time required to move an additional 50 mm [s]

L ₁ : Movement distance of weight (=50 mm)

L ₂ : Plate thickness of bottom hole [m]

S: Average value of the cross-sectional area of the bottom area of the columnar weight and the hollow area inside the cylinder (that is, the inner diameter part) [㎡]

In addition, as a method of filling the foamed aggregate mixture into the mold forming space (so-called cavity), direct pressurization by a piston in the cylinder, filling by supplying compressed air into the cylinder, pressure feeding by screws, etc., and sloshing, etc. have. However, direct pressurization by a piston and charging by compressed air are preferable from the charging speed and stability of charging by uniform pressurization of the expanded aggregate mixture.

The evaporation of moisture from the foamed aggregate mixture filled in the mold molding space (so-called cavity) is, for example, heat from the heated mold, the flow of heated air into the mold molding space (so-called cavity), and the use of both. Done by the method.

〔Manufacture of castings using molds〕

The mold produced by using the mold aggregate mixture according to the present embodiment is used for casting of various metals or alloys. As a material of the molten metal used for casting, the following are mentioned, for example. In addition, the following pouring temperature indicates the temperature at which the following materials are dissolved to an appropriate degree for pouring.

Aluminum or aluminum alloy (Pouring temperature: for example, 670℃ ~ 700℃)

Iron or iron alloy (Pouring temperature: 1300℃ ~ 1400℃, for example)

Bronze (Pouring temperature: 1100℃ to 1250℃, for example)

Brass (Pouring temperature: for example, 950℃ to 1100℃)

Casting is performed, for example, by pouring molten metal made of the materials listed above into a space between the core as a mold and a mold, and then cooling to remove the mold.

Example

Hereinafter, the present disclosure will be described in more detail by examples, but the present disclosure is not limited to the following examples. In the following, "part" represents "part by mass" unless otherwise specified.

<Example A1>

The materials of the composition shown in Table 1 were stirred and mixed for about 5 minutes at about 200 rpm using a mixer (manufactured by AICOHSHA MFG. CO., LTD., a desk mixer) and foamed to prepare a foamed aggregate mixture.

The amount of the aqueous release agent (LC-9 prototype) was 0.05 parts by mass, and the equivalent of the functional group to the aggregate mixture was 1.0×10 ^-6 mol/kg.

Next, this expanded aggregate mixture was pressurized and filled with a cylinder surface pressure of 0.4 MPa in a mold for bending tests heated to 220° C. without applying a releasing agent to a cavity having a capacity of about 80 cm 3 (filling step).

Then, the foamed aggregate mixture filled in the heated mold was allowed to stand for 2 minutes, and moisture was evaporated by the heat of the mold to solidify the foamed aggregate mixture (solidification step).

After that, the core as a mold was taken out from the cavity of the mold.

The mold (that is, the core) did not remain in the cavity of the mold, and there were no cracks and flaws in the mold, and could be taken out.

A bending test piece was produced from this mold, and the bending strength was measured after 60 minutes. In addition, the measurement of the bending strength was performed according to the JACT test method SM-1 and the bending strength test method. As a result, the strength of 3.5 MPa was obtained, respectively. In addition, if the bending strength of the mold is 2 MPa or more, it is a strength that does not cause problems in handling of the mold, and it is a strength that can be sufficiently used as a mold.

<Example A2>

A core as a mold was obtained in the same manner as in Example A1, except that the amount of the aqueous release agent (LC-9 prototype) was changed to 0.5 parts by mass, that is, the equivalent weight of the functional group to the aggregate mixture was changed to 1.0 × 10 ^-5 mol/kg. .

The mold (that is, the core) did not remain in the cavity of the mold, and there were no cracks and flaws in the mold, and could be taken out.

A bending test piece was produced from this mold, and the bending strength was measured after 60 minutes. As a result, the strength of 3.0 MPa was obtained, respectively.

<Example A3>

A core as a mold was obtained in the same manner as in Example A1, except that the amount of the aqueous release agent (LC-9 prototype) was set to 0.01 parts by mass, that is, the equivalent weight of the functional group to the aggregate mixture was changed to 2.0 × 10 ^-7 mol/kg. .

The mold (that is, the core) did not remain in the cavity of the mold, and there were no cracks and flaws in the mold, and could be taken out.

A bending test piece was produced from this mold, and the bending strength was measured after 60 minutes. As a result, the strength of 3.2 MPa was obtained, respectively.

<Example A4>

Instead of the aqueous release agent (LC-9 prototype), a prototype liquid 8 (manufactured by TETRA Co., Ltd.) having a different chain structure was used, and the amount was 0.1 parts by mass, that is, the equivalent weight of the functional group to the aggregate mixture was 3.0× Except having changed to ^10-5 mol/kg, it carried out similarly to Example A1, and obtained the core as a mold.

The mold (that is, the core) did not remain in the cavity of the mold, and there were no cracks and flaws in the mold, and could be taken out.

A bending test piece was produced from this mold, and the bending strength was measured after 60 minutes. As a result, the strength of 3.0 MPa was obtained, respectively.

<Comparative Example A1>

The materials of the composition shown in Table 2 were stirred and mixed for about 5 minutes at about 200 rpm using a mixer (manufactured by AICOHSHA MFG. CO., LTD., a desk mixer) to foam to prepare a foamed aggregate mixture.

Next, this expanded aggregate mixture was pressurized and filled with a cylinder surface pressure of 0.4 MPa in a mold for bending tests heated to 220° C. without applying a releasing agent to a cavity having a capacity of about 80 cm 3 (filling step).

Then, the foamed aggregate mixture filled in the heated mold was allowed to stand for 2 minutes, and moisture was evaporated by the heat of the mold to solidify the foamed aggregate mixture (solidification step).

After that, the core as a mold was taken out from the cavity of the mold.

Since the mold (that is, the core) partially remained in the cavity of the mold, and cracks and flaws occurred in the mold, a bending test piece could not be produced.

<Comparative Example A2>

A core as a mold was obtained in the same manner as in Comparative Example A1, except that a dimethyl silicone type releasing agent was applied to the cavity of the mold before pressure filling of the foamed aggregate mixture into the mold.

The mold (that is, the core) did not remain in the cavity of the mold, and there were no cracks and flaws in the mold, and could be taken out.

A bending test piece was produced from this mold, and the bending strength was measured after 60 minutes. As a result, the strength of 3.5 MPa was obtained, respectively.

However, since the work of applying the mold release agent to the mold was performed, the time required for one cycle of molding the mold was increased by 10% compared to the case of Example A1.

<Example B1>

The materials of the composition shown in Table 3 were stirred and mixed for about 5 minutes at about 200 rpm using a mixer (manufactured by AICOHSHA MFG. CO., LTD., a desk mixer) to foam to prepare a foamed aggregate mixture.

The amount of the aqueous release agent (LC-9 prototype) was 0.05 parts by mass, and the equivalent of the functional group to the aggregate mixture was 1.0×10 ^-6 mol/kg.

Next, this expanded aggregate mixture was pressurized and filled with a cylinder surface pressure of 0.4 MPa in a mold for bending tests heated to 220° C. without applying a releasing agent to a cavity having a capacity of about 80 cm 3 (filling step).

Then, the foamed aggregate mixture filled in the heated mold was allowed to stand for 2 minutes, and moisture was evaporated by the heat of the mold to solidify the foamed aggregate mixture (solidification step).

After that, the core as a mold was taken out from the cavity of the mold.

The mold (that is, the core) did not remain in the cavity of the mold, and there were no cracks and flaws in the mold, and could be taken out.

A bending test piece was produced from this mold, and the bending strength was measured after 60 minutes. As a result, the strength of 3.2 MPa was obtained, respectively.

<Example B2>

Examples except that the amount of the aqueous release agent (LC-9 prototype (manufactured by TETRA Co., Ltd.) was 0.5 parts by mass, that is, the equivalent of the functional group to the aggregate mixture was changed to 1.0 × 10 ^-5 mol/kg) It carried out similarly to B1, and obtained the core as a mold.

The mold (that is, the core) did not remain in the cavity of the mold, and there were no cracks and flaws in the mold, and could be taken out.

A bending test piece was produced from this mold, and the bending strength was measured after 60 minutes. As a result, the strength of 2.8 MPa was obtained, respectively.

<Example B3>

Examples except that the amount of the aqueous release agent (LC-9 prototype (manufactured by TETRA Co., Ltd.) was 0.01 parts by mass, that is, the equivalent of the functional group to the aggregate mixture was changed to 2.0 × 10 ^-7 mol/kg) It carried out similarly to B1, and obtained the core as a mold.

The mold (that is, the core) did not remain in the cavity of the mold, and there were no cracks and flaws in the mold, and could be taken out.

A bending test piece was produced from this mold, and the bending strength was measured after 60 minutes. As a result, the strength of 3.3 MPa was obtained, respectively.

<Example B4>

Instead of the aqueous release agent (LC-9 prototype), a prototype liquid 8 (manufactured by TETRA Co., Ltd.) having a different chain structure was used, and the amount was 0.1 parts by mass, that is, the equivalent weight of the functional group to the aggregate mixture was 3.0× Except having changed to ^10-5 mol/kg, it carried out similarly to Example B1, and obtained the core as a mold.

The mold (that is, the core) did not remain in the cavity of the mold, and there were no cracks and flaws in the mold, and could be taken out.

A bending test piece was produced from this mold, and the bending strength was measured after 60 minutes. As a result, the strength of 4.1 MPa was obtained, respectively.

<Comparative Example B1>

The materials of the composition shown in Table 4 were stirred and mixed for about 5 minutes at about 200 rpm using a mixer (manufactured by AICOHSHA MFG. CO., LTD., a desk mixer) to foam, to prepare a foamed aggregate mixture.

Next, this expanded aggregate mixture was pressurized and filled with a cylinder surface pressure of 0.4 MPa in a mold for bending tests heated to 220° C. without applying a releasing agent to a cavity having a capacity of about 80 cm 3 (filling step).

Then, the foamed aggregate mixture filled in the heated mold was allowed to stand for 2 minutes, and moisture was evaporated by the heat of the mold to solidify the foamed aggregate mixture (solidification step).

After that, the core as a mold was taken out from the cavity of the mold.

Since the mold (that is, the core) partially remained in the cavity of the mold, and cracks and flaws occurred in the mold, a bending test piece could not be produced.

<Comparative Example B2>

A core as a mold was obtained in the same manner as in Comparative Example B1, except that a dimethyl silicone type releasing agent was applied to the cavity of the mold before filling the foamed aggregate mixture under pressure into the mold.

The mold (that is, the core) did not remain in the cavity of the mold, and there were no cracks and flaws in the mold, and could be taken out.

A bending test piece was produced from this mold, and the bending strength was measured after 60 minutes. As a result, the strength of 3.0 MPa was obtained, respectively.

However, since the work of applying the release agent to the mold was performed, the time required for one cycle of molding the mold was increased by 10% compared to the case of Example B1.

In addition, the details of each material shown in Tables 1 to 4 are as follows.

(Aqueous release agent)

·Manufacturer: TETRA Co., Ltd., Product name: LC-9 prototype

Ingredients: Special silicone water dispersion

(Functional group: carbonyl group, chain structure: siloxane chain)

Equivalent weight of functional group in dispersion: 2.0×10 ^-3 mol/kg

·Manufacturer: TETRA Co., Ltd., Product name: Prototype amount 8

Ingredients: Special wax water dispersion

(Functional group: carbonyl group, chain structure: carbon chain)

Equivalent weight of functional group in dispersion: 3.0×10 ^-2 mol/kg

(aggregate)

Natural silica (Flattery Sand, Cape Flattery Silica Mines)

Artificial aggregate (ESPEARL#60, Yamakawa Sangyo Co., Ltd.)

(Water-soluble caking agent)

Polyvinyl alcohol (Manufacturer: KURARAY CO., LTD., product name: PVA105)

Sodium silicate (water glass, molar ratio 2.0, Fuji Chemical Co., Ltd., No. 1)

(Water-soluble foaming agent)

Anionic surfactant (ether sulfate Na salt, NOF Corporation)

In addition, as for the indication of Japanese application 2018-55302, the whole is incorporated into this specification by reference.

All documents, patent applications, and technical standards described in this specification are specifically incorporated by reference, and to the same extent as when individually recorded, the individual documents, patent applications, and technical standards are incorporated by reference in this specification. do.

Claims (11)

aggregate,
Water soluble binders,
Water soluble blowing agent,
Aqueous release agents, and
water,
Aggregate mixture for a mold containing. The method of claim 1,
The aqueous release agent is a chain structure material having at least one functional group selected from a carboxyl group, a carbonyl group, a silanol group, and a phenol group, having a proton donating agent acting as the water-soluble binder. The method of claim 2,
The content of the aqueous releasing agent is 2.0×10 ^-7 mol/kg or more and 1.0×10 ^-4 mol/kg or less with respect to the mold aggregate mixture as an equivalent of the functional group acting as the water-soluble binder. The method according to any one of claims 1 to 3,
The water-based release agent, having a performance that does not interfere with the foaming action, aggregate mixture for a mold. The method according to any one of claims 1 to 4,
The water-soluble binder comprises at least one selected from inorganic salts and organic salts that function with functional groups of the aqueous release agent, and carbohydrates that form a glycosidic bond with the aqueous release agent. The method according to any one of claims 1 to 5,
The aggregate is at least one of natural silica sand and artificial sand, an aggregate mixture for a mold. The method according to any one of claims 1 to 6,
The particle size (AFS index) of the aggregate is 40 or more and 120 or less, an aggregate mixture for a mold. The method according to any one of claims 1 to 7,
The water-soluble foaming agent is a surfactant, aggregate mixture for a mold. The method according to any one of claims 1 to 8,
Aggregate mixture for molding, containing air bubbles by foaming. aggregate,
Water soluble binders,
Water-soluble blowing agent, and
Aqueous release agents,
A template containing. a) A foamed aggregate mixture preparation process in which foaming is produced in the molded aggregate mixture by stirring the aggregate, water-soluble binder, water-soluble foaming agent, water-soluble foaming agent, and water-containing aggregate mixture for a mold to prepare a foamed aggregate mixture containing air bubbles. ,
b) a filling step of filling the foamed aggregate mixture into a space for mold molding in a mold,
c) a mold shaping step of evaporating the moisture of the charged foam aggregate mixture to solidify the foam aggregate mixture to form a mold, and
d) a takeout step of taking out the molded mold from the space for mold molding,
Molding method of a mold having a.